Date: Sun, 26 Jan 2003 22:23:05 EST
Reply-To: Oxroad@AOL.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jeff Oxroad <Oxroad@AOL.COM>
Subject: clutch pedal buzzing with vibration
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Just got my 83.5 Westy back from Fast German Auto where the clutch was
allegedly replaced. The clutch pedal now vibrates very noticably with a buzz
at right around 3000 RPMs in first gear when accelerating from a stop. The
vibration sometimes occurs in second gear while accelerating through the same
RPMs. The vibration does not happen every time. The vibration starts at about
3000 RPMs and up to maybe 3800 RPMS. It might stop at the higher revs or
might just be difficult to hear as the engine gets louder at increased RPMs.
If I touch the clutch pedal slightly or grab it with my hand the buzzing will
stop, but the vibration is still somewhat apparent seeming to mimic a buzz
from the rear at the same frequency. The buzz from the rear however is
difficult to hear. Also if I start from a stand still and begin moving
forward in first gear, accelerating to 3000 RPMS and the buzzing vibration
starts, I can then drive steady in the 3000 RPM range in first gear, gently
pull the trans out of first gear into neutral without depressing the clutch
the buzzing continues as long as I keep the revs steady at about 3000. (I can
pull the bus out of gear gently without the clutch by backing off the
accelerator a tiny bit- still keeping in the buzzing RPM range-- this in a
matching revs kind of way) The buzzing will continue as long as I keep the
RPMS steady at 3000 even out of gear and coasting. The buzzing will continue
if I stop the vehicle in this coasting scenario even at a full stop, but
never touching the clutch pedal. However I cannot sit still and get the
buzzing to occur by merely accerating to 3000 RPMs.
So questions are:
1.When installing a new clutch and supposedly pressure plate and hopefully
throwout bearing will the clutch need adjustment? (The only adjustment I know
of in this system is the clearance between the clutch pedal piston rod or
push rod and the clutch master cylinder up under the dash. will this
adjustment change with a new clutch plate?)
AND
2. I'm not sure I understand that if the vibration is coming from the
transmission or even the engine, why the clutch pedal would vibrate. Because
the clutch release is a hydralic system and the metal line has the length of
rubber hose back by the transmission that it would seem would absorb any
vibration that would want to head directly to the clutch pedal. The clutch
pedal bushings are a bit worn so a slight side to side bit of play can be
felt in the clutch pedal if so moved--so if the vibration is coming from the
transmission is it just coincidence that the clutch pedal bushings are worn
and therefore the pedal vibrates louder than the rest of the parts on the
vehicle? In this scenario I assume the whole bus in vibrating in a largely un
noticed way until the vibration reaches the loose clutch pedal.
I should add the front engine mount, that is the one in front of the
transmission, does have a small visible crack in it. And while it should be
replaced, I'm not sure this buzzing vibration would be a result of that. And
the crack has been there for a good 6-8 months with no previous symptoms. (I
asked one of the owners of FGA when I dropped the bus to get the clutch what
it would cost to have them replace the front engine mount while they were
under the bus. The owner replied "They never go bad." I wish I had turned the
bus around right then knowing they actually do and mine actually had.)
I suspect something possibly like the release shaft bushings might be worn
and the release shaft is vibrating--but this it seems would not effect the
clutch pedal. Could be the trowout bearing is ungreased and vibrating if the
morons at FGA did not put in a new one.
I'll also check the mounting bolt and nut torques tomorrow. For those who
didn't follow the last post of troubles I had with Fast German Auto, it
should be noted that they were particularly sloppy, cracked my dash board and
spilled brake fluid behind the dash without ever admitting to either.
3. On this brake fluid note--is it possible the fluid could have been forced
up out of the brake fluid resevoir by the "mechanic" pushing on the clutch
slave cylinder while under the bus? My theory on this is while re-installing
the transmission with the new pressure plate, possibly thicker than the one
that was in the vehicle pushed back on the throwout bearing rotating the
release shaft forcing the clutch lever up a bit higher than it had been which
compressed the slave cylinder piston forcing fliud forward into the clutch
master cylinder and out the top of the resevior. The fluid in the resevior by
the way is above the "max" fill line at the top since I got it back from
FGA--and is in fact full to the top. I will syphon some off the top ASAP.
Also there was no buzzing before the new clutch was installed.
TIA
Jeff
83.5 Westy
LA,CA